Technical Abstract:
Consensus chloroplast (cp) primers that possess hyper-variable cp DNA regions have been developed in several species. Although a limited number of such primers have been constructed from the tobacco cp genome, they may be of minimal value for studying the evolutionary relationships among closely related taxa in Cucurbitaceae. Therefore, a study was designed to provide additional genetic tools for the evolutionary assessment in this plant family by employing selected cp cucumber regions that were sequenced using consensus primers developed from Arabidopsis thaliana L., Nicotiana. tabacum, L., and Spinacia oleracea L. Mono-nucleotide repeats (A or T ' 7) in cucumber cp DNA sequences were used to select 24 consensus cp primer (CCP) pairs for evaluation in cucurbit species. All CCP pairs produced amplicons using cucumber (Cucumis sativus L.), melon (Cucumis melo L.), squash (Cucurbita pepo L.), and bottle gourd [Lagenaria siceraria (Molina) Standl.] DNA, except one pair (18086-F & 18935-R) that produced no bands in the bottle gourd accession sampled. Sequence analyses using four CCP primers, (1571-F, 13876-F, 15358-R, and 31173-F) detected highly polymorphic sequences among these species. These results indicate that these CCP pairs, along with previously developed 23 consensus cp SSR (ccSSRs; Chung and Staub, 2003), will be useful for detection of hyper-variable cp DNA regions in the Cucurbitaceae, and, thus, will likely be of value for the evolutionary studies in the Cucurbitaceae.